Push button switch mechanism and method of assembly



April 2s, 1970 B. J. GOLBECK am. 3,509,293

PUSH BUTTON SWITCH MECHANISM AND METHOD OF ASSEMBLY WM m Z@ 59am/zij. Q9

April 28, 1970 a. J. GoLBEcK ETAL 3,509,293

PUSH BUTTON SWITCH MECHANSM AND METHOD OF ASSEMBLY Filed Jan. 8, 1968 l Y 3 Sheets-Sheet 2 April 28, 1970 Q J, GOLBECK ETAI, 3,509,293

PUSH BUTTON SWITCH MECHANISM AND METHOD OF ASSEMBLY 3 Sheets-Sheet 3 Filed Jan. 8, 1968 United States Patent Office 3,509,293 Patented Apr. 28, 1970 3,509,293 PUSH BUTTON SWITCH MECHANISM AND METHOD OF ASSEMBLY Bernard J. Goldbeck, Crystal Lake, and John H. Williams,

Barrington, Ill., assignors to Oak Electro/Netics Corp.,

a corporation of Delaware Filed Jan. 8, 1968, Ser. No. 696,186 Int. Cl. H01h 9/26, 9/02 U.S. Cl. 200-5 13 Claims ABSTRACT OF THE DISCLOSURE A modular push button switch assembly which 1ncludes a plurality of standardized housing units, one for each push button switch, and complementary means on each of said housing units for interconnecting the housing units together side by side in a row of any desired number of switches. A plurality of stationary contact clips and a contact carrying slide member are mounted on each of the individual housing units before the units are interconnected together and each of the slide members moves the contact carried thereby into and out of engagement with one or more of the stationary contact clips on the respective housing unit. The housing units are provided with means for mounting elongated latch bars, block-out mechanisms and reinforcing plates along the row of units when connected together.

BACKGROUND OF THE INVENTION Heretofore, plural push button switches were generally manufactured only in a limited number of standard sizes, because many elements of the frame or contact carrying cards and operating mechanisms were designed for the number of switches in a row. The operative components of the assembly, as the stationary contacts, the contact carrying slide members, the push rods, the latch bar, the block-out mechanism, and so on, had to be subsequently assembled to the custom-made framework. Not only are such structures complicated and expensive to manufacture because of the custom-made housing and the multiple parts comprising the assembly, but more important the custom-made aspect of the assemblies render them inflexible for the variety of uses for which they are intended. This invention is designed to solve such problems by providing a modular type push button switch assembly having standardized housing units for each push button switch.

SUMMARY OF THE INVENTION An object of this invention is to provide a new and improved push button switch mechanism and method of assembly.

Another object of this invention is to provide a modular push button switch assembly which includes a plurality of push button switches each having an identical housing unit, with the housing units having complementary means for interconnecting the units side by side in a row of any desired number.

Yet a further object of this invention is to provide a modular push button switch assembly of the character described wherein each of the housing units has means in alignment with means on the other housing units for receiving an elongated latch bar for holding the push buttons in their depressed positions, and similar means for receiving an elongated block-out mechanism for preventing more than one push rod from being depressed at any one time, both the latch Abar and block-out mechanism extending along the row of housing units and being mounted thereon.

Another object of thies invention is to provide a modular push button switch of the character described which includes a push-push mechanism for each of the push rods, the mechanism including a first portion on the push rod and a second portion mounted on the respective housing unit.

Still another object of this invention is to provide spring means between each of the housing units and their respective push rods to urge the push rods in a given direction, the spring means being easily removable from the housing units after the entire structure is assembled to change the operating pressure.

A further object of this invention is to provide a method of assembling a modular push button switch construction of the character described.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a bottom plan view of a modular push button switch assembly embodying the invention;

FIG. 2 is a bottom plan View, partially cut away, of the left-hand push button switch as viewed in FIG. l, with the block-out mechanism removed to facilitate the illustration;

FIG. 3 is a top plan view of the push button switch of claim 2;

FIG. 4 is a sectional view taken generally along the line 4 4 of FIG. 1;

FIG. 5 is a sectional view taken generally along the line 5-5 of FIG. 4;

FIG. 6 is a view taken generally in the direction of line 6---6 of FIG. 2, partially cut away to show the means for connecting adjacent housing units together;

FIG. 7 is a view similar to that of FIG. 6, with one of the housing units turned from that shown in FIG. 6 and illustrating thel units in their initial relative angular position of being connected together; l

FIG. 8 is a view similar to that of FIGS. 6 and 8, with the housing units in an intermediate relative angular position of being connected together;

FIG. 9 is an exploded perspective view, partially cut away, of the left-hand push button switch as viewed in FIG. 1; and

FIG. 10 is a bottom plan view of a single push button switch embodying a push-push mechanism.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in greater detail, the modular push button switch assembly of this invention is shown in FIG. l and includes a plurality of modules or identical housing units, indicated generally as 12, which are generally rectangular and box-like in shape, as best seen in FIG. 9. The housing units are molded of plastic material and have means (described below) formed integrally therewith for interconnecting the units together side by side in a row of any desired number. For illustration purposes, FIG. 1 shows six identical housing units 12 connected together in a row to provide for six push button switches.

Referring to FIGS. 6 through 9, each of the boxlike housing units 12 have an L-shaped boss 14 protruding outwardly from one side wall 16 for insertion through an opening 18 in an opposite side wall 20 of an adjacent housing unit 12 when the two housing units are turned at right angles to `their aligned position shown in FIG. l. FIG. 7 shows two housing units positioned for inserting the boss 14 of one housing unit into the opening 18 in an adjacent unit. The frames are then rotated in the direction of arrow A in FIG. 8. The L-shaped boss forms a transverse leg 21 which locks behind a lip 22, along one edge of the vopening 18, when the adjacent housing units are aligned as shown in FIG. 1.

Referring to FIGS. 3 and 9, a slide member 24, preferably molded of thermoplastic material, is positioned in a trough, generally indicated 26 (FIG. 9), in each of the housing units 12 with a rib 28 on the slide member protruding through a slot 30 in the bottom wall 31 of the housing unit. Slide member 24 carries a plurality of contacts 32 for engaging one or more of a plurality of stationary double Wipe contacts 34 disposed on opposite sides of-the slot 30, on the outside of the housing units 12. As best seen in FIG. 9, each contact 32 has a pair of tongues 32a which are inserted through a pair of slots 35 in the slide members 24 from the outside of the boxlike housing units. In the embodiment illustrated (FIG. 3) the slide member 24 carries four contacts 32, and three stationary contacts 34 are provided for each contact 32. The double wipe contacts 34 are riveted through holes 36 (FIG. 9) extending through the housing units 12 to the inside thereof along trough 26. For ease of assembly, the slide members 24, the contacts 32 carried by the slide members, and the double wipe stationary contacts `34 are assembled to their respective housing units 12 before the frame units are connected together side by side.

Again referring to FIG. 9, in one embodiment of the invention an elongated latch bar 38 is inserted through aligned openings 40 in the side walls 16 and 20 of the connected housing units from one end of the row, the right end as seen in FIG. l. The latch bar overlies the slide members 24 which are disposed in the troughs 26 in each of the housing units 12. A leg 38a is stamped out of one end of the latch bar (the left end as viewed in FIGS. 1, 2 and 9), and a coil spring 40 is positioned about the leg to urge the latch bar to the right in the drawings. The leg extends longitudinally of the latch bar 38 and the coil spring 40 bears against the inside surface of the wall 20 of the leftmost housing unit as viewed in FIG. 1 to urge the latch bar to the right.

After the latch bar 38 is inserted through the openings 40 in the side walls of the connected housing units 12, a push rod 42 is positioned within eachV of the box-like housing units 12 so as to overlie the latch bar 38. Each push rod 42 has one end 42a protruding through a notch or recess 44 in an end wall 46 of its respective housing unit 12. The push rods have shoulders 48 which abut against the inside surface of end wall 46 when the push rods are in their extreme outer or raised position. A coil spring 48 is disposed at the opposite end of each of the push rods 42. Each spring 48 is positioned about a leg 50 stamped 'out of the push rod and is seated in a recess 52 in the opposite end wall 56 of the housing unit 12. 'Phe leg 50 is offset from the remainder of its push rod end 56 so that the end 56 of the push rod may reciprocate through a slot 58 in the end wall 54 of the housing unit.

To connect the push rods 42 to the slide members 24 and the latch bar 38, each push rod has a tongue 60 stamped therefrom and bent to protrude inwardly toward its slide member 24 and the latch bar. The tongue 60 not only actuates the latch bar but also extends through the latch bar into a slot 62 in the respective slide member 24 so that the slide member reciprocates with the push rod to engage or disengage the contacts 32 carried thereby with the stationary contacts 34 on the respective housing units 12. The latch bar 38 is operated in a known manner in that the tongue 60 of a push rod 42 engages a cam surface 64 on the latch bar 38 and moves the latch bar to the left in the drawings as the push rod is depressed. Coil spring 40 is thereby compressed and, when the tongue 60 moves behind a shoulder 66 below the cam surface, the push rod is locked in its depressed position. The push rod 42 is held in its depressed position until another push rod is subsequently depressed and its tongue 60 engages a similar cam surface 64 to move the latch bar 38 to the left and release the previously depressed push rod.

In order to maintain the push rods in position within their respective housing units and also to maintain the housing units rigidly in a row, a reinforcing channelshaped top plate 68 is positioned longitudinally across the adjacent end Walls 46 of the row of frame units 12 with the outer ends 42a of the push rods 42 extending through 'a plurality of slots 68u in the bight portion of the channel-shaped reinforcing plate 68. The reinforcing plate has a plurality of tabs 70 protruding from each rib or leg of the channel and are bent inwardly to grip the housing units and hold them rigidly in the row. In the illustrated embodiment, two tabs are provided along each leg of the channel for each housing unit and, as viewed in FIG. 9, two tabs on one leg are bent inwardly adjacent the inside surface of side walls 16 and 20 of the housing units. Referring to FIG. 3, the two tabs on the other leg are bent through holes v72 in the bottom wall 31 of the housing units.

After the reinforcing plate 68 is secured to the connected row of housing units, push buttons 73 are positioned by frictional engagement onto the ends 42a of each push rod 42.

It can be seen that in order to provide a plurality of self-contained push button switch assemblies of any given number rigidly connected in a row, the only elements described above which must be varied in dimensions are the latch bar 38 and the reinforcing channel plate 68. Both of these members are preferably made of metal and can easily be cut to any desired length and kept on hand in a variety of lengths depending upon the number of push buttons desired. All other elements described above are identical so as to provide a push button switch assembly comprising a plurality of self-contained modular units. The latch `bar is an optional mechanism and is not utilized in all types of push button switches. In addition, since the housing units 12 are molded of plastic material, they provide a bearing means for the latch bar 38, the push rods 42 and the slide members 24. The plastic housing units also provide a high-grade dielectric base for the contacts.

As best seen in FIGS. 1 and 9, the housing units of this invention have means for mounting a block-out mechanism, indicated generally at 74, to prevent more than one push rod 42 from being depressed at any one time. The block-out mechanism is of a cam type and includes an elongated backing plate 76 and an elongated channel plate 77 within which a plurality of cams 80 slide back and forth longitudinally of the row of switches. The channel plate 78 is positioned and secured to the backing plate 76 by a plurality of tabs 82 on the channel plate which extend through holes 84 in the backing plate and are bent inwardly on the opposite side of the backing plate to hold the channel plate thereto. After the block-out mechanism 74 is assembled, the mechanism is mounted longitudinally across the row of housing units 12 for cooperation with the push rods 42. The side walls 16 and 20 of the housing units 12 have slots or recesses 86 aligned longitudinally along the row of connected units. The walls 16 and 20 of adjacent housing units receive reduced neck portions 88 of the backing plate 76 of the block-out mechanism 74. As can be seen in FIG. l, the reduced neck portions 88 are wide enough to accommodate the combined thickness of both side walls of adjacent housing units 12. Referring to FIGS. 4 and 9, the block-out mechanism is snapped in place by snapping the backing plate 76 under detents 89 on the inside of the side Walls of the housing units. The backing plate has a plurality of arms 76a which bear aga/inst one leg of the channelshaped reinforcing plate 68. A boss 90` (FIG. 9) protrudes from the push rods 42 and extends through openings 92 for engaging the cams 80 and moving the cams longitudinally of the block-out mechanism to permit the push rods to be depressed. However, the cams are spaced to have a total clearance between the cams equal to the width of a single boss 92 and thereby prevent more than one push rod from being depressed at any one time. Referring to FIG. 9, a tongue 94 protrudes outwardly from the backing plate 76 through a slot 96 in the endmost cam members 80 of the row thereof to limit the movement of the extreme opposite cam members 80. Here again, the backing plate 76 and the channel plate 78 of the block-out mechanism 74 are preferably formed of metallic material which is easily cut to any desired length and, since one cam member 80 is disposed between each of the push rods, the block-out mechanism 74 is easily adapted for any desired number of individual push button assemblies.

Referring to FIG. 9, the housing units also have means for receiving a push-push latch mechanism as an alternative to the latch bar 38. A push-push mechanism, generally designated 100 (FIG. 9) is provided for each housing unit and holds the respective push rod 42 in its depressed position and releases the depressed push rod in response to subsequent further depression of the same rod. The basic operation of the push-push mechanism is known in the art and includes a first portion or star wheel 102 pivotally secured to the push rod 42 and a second portion 104 comprising a flat plate mounted on the housing unit 12 overlying the push rod 42. The plates 104 have tabs 104a on opposite edges thereof for insertion into slots 105 (FIG. 9) in the side walls 16 and 20 of the housing units below recesses 82. The plate rests on a shoulder 105a at the base of each of the recesses 82. The plate -4 has an aperture, generally designated 106, through which the star wheel 102 extends. The configuration of the aperture 106 is such as to comprise a plurality of cam surfaces and keeper surfaces cooperating with the marginal edge of the star wheel 102 -to provide the push-push action. On depressing the push rod 42 in the direction of arrow B (FIG. 10), surface 102a of the star wheel engages cam surface 106a of aperture 106 causing the star wheel to rotate a few degrees in the direction of arrow C. On releasing the push rod, the star wheel and push rod move under the force of spring 48 in a direction opposite arrow B until surface 102b of the star wheel abuts surface 106b of aperture 106 and locks the push rod 42 in its depressed position, with the star in a position shown in phantom in FIG. 10. Subsequently depressing the same push rod in the direction of arrow B will cause surface 102e` of the star wheel 102 to engage the cam surface 106b of aperture 106 and will rotate the star wheel inthe direction of arrow C to a position one quarter turn from the original position of FIG. 10. Releasing of the push rod then causes surface 102d of star wheel 102 to engage cam surface 106b of aperture 106 rotating the star wheel another quarter -turn in the direction of arrow C and permit the push rod 42 to return to its original position under the biasing of spring y48, with the star wheel positioned 180 from its original position.

As best seen in FIGS. 2 and l0, the coil springs 48 are easily removable from the assembled switches to permit changing the spring after assembly to adjust the operating pressure of the spring.

A brief description of the method of assembly of the form of the invention shown in FIGS. 1-9` will now be presented. The contact-carrying slide members 24 are first positioned in the troughs 26v on the inside of the box-like housing units 12, the number of housing units being dependent upon the number of push button switches required for a given row. Contacts 32 are then assembled to the slides 24 as described above and the double wiping stationary contacts 34 are riveted to the back of each of the housing units as shown in FIG. 3. 'I'he housing units, with the slide members 24 and contacts 34 mounted thereon, are then connected together side by side in a row of any desired number by the cooperation of plugs 14 and apertures 1S as described above. Latch bar 38 is then inserted through the entire row of connected housing units from one end thereof (the right end as shown in FIG. l) and coil spring 40 is placed over leg 38a on the left end of the latch bar. The push rods 42 are then positioned within the box-like housing units 12 with the outer ends 42a of the push rods extending through recesses 34 in the end walls 446 of the housing units. The coil springs 48 are placed around the legs 50 of the push rods 42 with one end of the springs seated in the recesses 52 in the end wall 54 of the housing units. The block-out mechanism 74 is then assembled as described above and positioned with thevreduced neck portions 88 thereof within recesses 86 in the adjacent side walls of the connected housing units and maintained in such a position by the detents 89 and the arms 76a of the backing plate 76 of the block-out mechanism. The reinforcing plate 68- is then positioned along the end walls 46 of the connected housing units with the outer ends 42a of the push rods extending through the slots 68a in the reinforcing plate 68. The tabs 70 on the reinforcing plate are then bent inwardly to secure the plate to the end walls 46 of the housing units. Push buttons 73 are then positioned by frictional engagement on the protruding ends 42a of the push rods.A

In the push-push form of the invention shown in FIG. 10, plate 104 is positioned within the housing unit 12 at any time after the push rods 42 have been positioned within the housing units.

The unique modular structure shown herein is equally adaptable for other types of switches, such as momentary push button switches and the like.

The housing units, latch bar or push-push mechanism, push rods, block-out mechanism, and top plate are removably assembled without screws or other fastening means and the housing units act as bearing means for the slide members, push rods and latch bar.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as some modications will be obvious to those skilled in the art.

We claim:

1. A modular push button switch assembly, comprising: a plurality of housing units, one for each push button switch; connecting means on each of said housing units for interconnecting the housing units together side by side for any desired number of push button switches to form a framework for said assembly; contact means mounted on each of said housing units; a push rod mounted on each of said housing units for reciprocating movement relative to said contact means; and complementary contact means moved by each of said push rods into and out of engagement with said first named contact means on the respective housing unit.

2. The modular push button switch assembly of claim 1 wherein said irst named contact means comprises a plurality of stationary contact clips mounted on each of said housing units, and including a contact-carrying slide member mounted on each of said housing units for reciprocating movement relative to the housing units to move the contact carried thereby into and out of engagement with one or more of said contact clips, each of said push rods being mounted for reciprocating movement in the same direction as said slide members and engaging its respective slide member to actuate the slide member in response to reciproacting movement of the push rod.

3. The modular push button switch assembly of claim 1 wherein said means for connecting the housing units together includes complementary means on adjacent housing units to lock the units together.

4. The modular push button switch assembly of claim 1 wherein said housing units are connected together in a row and said push rods are in alignment along said row of housing units, and including an elongated latch bar extending along said row of connected housing units and having means cooperating with each of said push rods to hold a push rod in a depressed position and to release the depressed push rod in response to subsequently depressing any other push rod, and means on each of said housing units cooperating when the units are connected together for receiving said latch bar to maintain the latch bar in position for cooperating with said push rods.

5. The modular push button switch assembly of claim 4 wherein said latch bar slides in a direction transverse to the direction of movement of said push rods, said housing units when connected together providing bearing means for said latch bar.

6. The modular push button switch assembly of claim 1 wherein said housing units are interconnected together in a row, and including a reinforcing plate extending across the row of connected housing units and having means for maintaining the units rigidly in said row.

7. The modular push button switch assembly of claim 6 wherein said push rods are received `in open recesses in said housing units, said reinforcing plate including a plurality of slots through which said pushrods-extend to hold the push rods in said recesses in said housing units.

8. The modular push button switch assembly of claim 1 wherein said housing units are connected together in a row, and including an elongated block-out mechanism extending along said row of connected housing units and cooperating with means on said push rods to prevent more than one push rod from being depressed at any one time, and means on each of said housing units cooperating when the units are connected together to hold the block-out mechanism in position.

9. The modular push button switch assembly of claim 1 including a push-push latch mechanism for each of said push rods to hold a push rod in a depressed position and to release the depressed push rod in response to subsequently depressing the same push rod, said push-push mechanism including a first portion on eachv of said push rods and a cooperating second portion on the respective housing unit.

10. The modular push button switch assembly of claim 1 including resilient means between each of said housing units and their respective push rods to urge the push rods in a given direction, with means permitting said resilient means to be easily removable from its housing unit after the modular push button switch is assembled.

11. A modular push button switch assembly, comprising: a plurality of identical housing units, one for each push button switch, said housing units each having complementary means for interconnecting the units together side by side in a row of any desired number; a plurality 'of stationary contact clips mounted on each of said housing units; a contact-carrying slide member mounted on each of said housing units for reciprocating movement relative to the housing units to move the contacts carried thereby into and out of engagement with one or more of said contact clips; a push rod mounted on each of said housing units for reciprocating movement in the same direction as said slide members, each of said push rods having one end protruding from its housing unit and havingmeans engageable with its respective slide member to actuate the slide member, and sald push rods being positioned by said housing units in alignment along said row; a latch -bar extending along said row of connected housing units for holding a push rod in a `depressed position and releasing the depressed push rod in response to subsequently depressing any other push rod; means on each of said housing units in alignment when the units are connected together for receiving said latch bar and holding the latch bar in position for cooperating with said push rods; a block-out mechanism spanning said row of connected housing units and cooperating with means on each of said push rods to prevent more than one push rod from Ibeing depressed at any one time; means on each of said housing units in alignment when the units are connected together to hold said block-out mechanism in position for cooperating with said push rods; and a push button mounted on said 011e end of each of said push rods. 12. The modular push button switch assembly of claim 11 including a reinforcing plate spanning adjacent ends of said interconnected housing units to maintain said housing units rigidly in said row. f

13. The modular push button switch assembly of claim 11 wherein said latch bar slides transversely of said push rods; said housing units being molded of plastic material and providing bearing means for said latch bar, said push rods and said contact-carrying slide members.

References Cited `UNITED STATES PATENTS 3,365,555 1/1968 Ponsy 200-18 XR 2,831,075 4/1958 Dumke et al. 3,271,530 9/1966 Wirsching.

ROBERT K. SCHAEFER, Primary Examiner I. R. SCOTT, Assistant Examiner U.S. C1. X.R. 200-168 

